grade=[100,90,87,76,98]
print("袁列表",grade)
grade.sort()
print("升序",grade)
grade.sort(reverse=True)
print("降序",grade)

char=["Angel","Tom","cat","pet"]
char.sort()
print("区分字母大小写:",char)
char.sort(key=str.lower)
print("不区分字母大小写:",char)